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To prospectively assess T2 mapping characteristics of normal articular cartilage and of cartilage at sites of arthroscopic repair, including comparison with histologic results and collagen organization assessed at polarized light microscopy (PLM).Study protocol was compliant with the Canadian Council on Animal Care Guidelines and approved by the institutional animal care committee. Arthroscopic osteochondral autograft transplantation (OAT) and microfracture arthroplasty (MFx) were performed in knees of 10 equine subjects (seven female, three male; age range, 3-5 years). A site of arthroscopically normal cartilage was documented in each joint as a control site. Joints were harvested at 12 (n = 5) and 24 (n = 5) weeks postoperatively and were imaged at 1.5-T magnetic resonance (MR) with a 10-echo sagittal fast spin-echo acquisition. T2 maps of each site (21 OAT harvest, 10 MFx, 12 OAT plug, and 10 control sites) were calculated with linear least-squares curve fitting. Cartilage T2 maps were qualitatively graded as "organized" (normal transition of low-to-high T2 signal from deep to superficial cartilage zones) or "disorganized." Quantitative mean T2 values were calculated for deep, middle, and superficial cartilage at each location. Results were compared with histologic and PLM assessments by using kappa analysis.T2 maps were qualitatively graded as organized at 20 of 53 sites and as disorganized at 33 sites. Perfect agreement was seen between organized T2 and histologic findings of hyaline cartilage and between disorganized T2 and histologic findings of fibrous reparative tissue (kappa = 1.0). Strong agreement was seen between organized T2 and normal PLM findings and between disorganized T2 and abnormal PLM findings (kappa = .92). Quantitative assessment of the deep, middle, and superficial cartilage, respectively, showed mean T2 values of 53.3, 58.6, and 54.9 msec at reparative fibrous tissue sites and 40.7, 53.6, and 61.6 msec at hyaline cartilage sites. A significant trend of increasing T2 values (from deep to superficial) was found in hyaline cartilage (P.01). Fibrous tissue sites had no significant change with depth (P.59).Qualitative and quantitative T2 mapping helped differentiate hyaline cartilage from reparative fibrocartilage after cartilage repair at 1.5-T MR imaging.

To investigate the temporal prevalence of a rim of increased signal intensity in the subcortical part of the patella at T2-weighted magnetic resonance (MR) imaging after arthroscopic knee surgery or knee injury.The prospective and retrospective components of the study were performed after receiving approval from the institutional research ethics board. Written informed consent was obtained for the prospective component of the study. The need for informed consent was waived for the retrospective component of the study. The authors performed a prospective evaluation of serial MR images of the knee of four patients (three men and one woman; age range, 28-53 years; mean age, 36.8 years) after arthroscopic anterior cruciate ligament (ACL) reconstruction. They also performed a retrospective review of MR images of the knee from 90 consecutive patients (59 male and 31 female patients; age range, 13-66 years; mean age, 34.6 years) referred for the evaluation of an ACL injury. All imaging studies were evaluated in consensus by two musculoskeletal radiologists for the presence of a rim of increased signal intensity in the subcortical part of the patella at T2-weighted imaging. The presence of this signal intensity pattern was correlated with the time to imaging from surgery or joint injury. Logistic regression modeling was performed with increased subcortical signal intensity as the outcome and a second-degree polynomial for elapsed time as the predictor.All four patients who underwent imaging prospectively after ACL surgery showed increased T2-weighted signal intensity in the subcortical part of the patella 12 weeks after surgery. None of the patients showed these signal intensity changes at 6 or 24 weeks. A subcortical rim of increased T2-weighted signal intensity was seen in the patella in 24 (27%) of the 90 consecutive patients who underwent imaging for the assessment of possible ACL injury. Significant independent differences were seen in the prevalence of increased T2-weighted signal intensity in the subcortical part of the patella when related to time between injury and MR imaging (P = .002), with an increase in prevalence as time since injury increased and a decrease in prevalence in patients who underwent MR imaging more than 20 weeks after injury (P = .013).Increased T2-weighted signal intensity in the subcortical part of the patella appears to be a subacute transient MR finding seen after knee surgery or injury.

To prospectively identify risk factors for neurologic complications related to cerebral angiography.A total of 2,899 consecutive cerebral digital subtraction angiograms obtained with nonionic contrast material were prospectively evaluated. Neurologic complications were categorized as transient (24 hours), reversible (24 hours to 7 days), and permanent (7 days). The neurologic complication rate was correlated with patient age, type of indication for catheter angiography, medical history, fluoroscopic time, number and size of catheters, type and number of vessels injected, operator experience, and the quartile in which the study was performed. The correlations were statistically analyzed with Fisher exact tests and a multiple logistic regression model.There were 39 (1.3%) neurologic complications in 2,899 procedures; 20 were transient (0.7%), five (0.2%) were reversible, and 14 (0.5%) were permanent. Neurologic complications were significantly more common in patients 55 years of age or older (25 of 1,361; 1.8%) (P =.035), in patients with cardiovascular disease (CVD) (20 of 862; 2.3%) (P =.004), and when fluoroscopic times were 10 minutes or longer (24 of 1,238; 1.9%) (P =.022). The neurologic complication rate was higher in procedures performed by fellows alone (24 of 1,878; 1.3%) compared with that when staff alone performed the procedures (three of 598; 0.5%), but the difference was not significant (P =.172). Neurologic complications were lower in the fourth quartile of the study (six of 171; 0.9%) compared with the first quartile (16 of 776; 2.1%), which was likely due to fewer patients being examined for carotid stenosis or ischemic stroke and fewer patients with CVD (P =.085).Age-related vascular disease accounted for the failure to lower the neurologic complication rate of cerebral angiography despite technical advances.

Two recent randomized controlled trials found vertebroplasty to be no better than a sham procedure; however, both trials included major deficiencies and are against the vast preponderance of evidence published to date.

To prospectively determine the comparability of 1.0-T extremity magnetic resonance (MR) imaging and 1.5-T conventional MR for the evaluation of the hand and wrist in assessment of patients with rheumatoid arthritis (RA).Institutional ethics approval and written informed consent were obtained. Thirty-two patients (30 women, two men; mean age, 52 years) with RA twice underwent MR of either the most symptomatic hand (n = 21) or wrist (n = 11), once performed with a 1.0-T extremity MR system and once with a 1.5-T conventional MR system. The MR examinations were independently assessed by two radiologists blinded to imaging platform and patient clinical information for erosions, synovitis, and bone marrow edema (BME), according to the Rheumatoid Arthritis MR Imaging Score (RAMRIS). One radiologist reevaluated all cases a second time to determine the intraobserver variability for each system. Patient comfort was assessed with a questionnaire. Intraclass correlation coefficients (ICCs) and smallest detectable differences (SDDs) were measured.ICCs for intermachine agreement were 0.97-0.99 for erosions, 0.88-0.97 for synovitis, and 0.98-0.99 for BME for both readers. The SDDs between the two systems, expressed as a percentage of the maximum score, ranged from 3.3% to 12.2% for erosions, from 7.4% to 14.8% for synovitis, and from 5% to 9.9% for BME for both readers. ICCs for interreader agreement ranged from 0.69 to 0.99 and for intrareader agreement, from 0.88 to 0.99. There were substantial differences in the subjective patient assessment of confinement, system noise, and difficulty with immobilization, and 95.8% of patients preferred examinations performed with extremity MR.The 1.0-T extremity MR system demonstrates synovial and osseous changes in RA equally as well as a 1.5-T conventional MR system and is preferred by patients.

To determine the accuracy of multidetector computed tomography (CT) in the detection of surgically important blunt bowel and/or mesenteric injury, to identify and describe the most reliable CT features of bowel and/or mesenteric injury, and to evaluate the performance of readers with different levels of expertise.Institutional review board approval was obtained for this retrospective case-control study of 96 subjects with laparotomy-confirmed findings: 54 consecutive patients with bowel and/or mesenteric injury (surgically important and unimportant) (32 male patients, 22 female patients; mean age, 40.4 years +/- 17.6 [standard deviation]; range, 16-86 years) and 42 matched patients without bowel and/or mesenteric injury (22 male patients, 20 female patients; mean age, 36.8 years +/- 20.1; range, 14-84 years) who underwent four-detector CT prior to surgery. A second-year radiology resident, an abdominal imaging fellow, and a staff abdominal radiologist, blinded to patient outcome, independently reviewed CT studies and recorded the probability of bowel and/or mesenteric injury on a five-point scale. Sensitivity and specificity were calculated for each reviewer, and areas under the receiver operating characteristic curve (AUCs) were compared.Thirty-eight (40%) of 96 patients had surgically important bowel and/or mesenteric injury, and 58 (60%) of 96 patients had either no or surgically unimportant bowel and/or mesenteric injury. Sensitivities of the three reviewers in the diagnosis of surgically important bowel and/or mesenteric injury ranged from 87% (33 of 38) to 95% (36 of 38); specificities ranged from 48% (28 of 58) to 84% (49 of 58). The only significantly better AUC belonged to the staff radiologist for surgically important mesenteric injury (P = .01). Bowel wall defect, extraluminal contrast material, thick large bowel, mesenteric vessel beading, abrupt termination of mesenteric vessels, and mesenteric vessel extravasation showed the best positive likelihood ratios for surgically important bowel and/or mesenteric injury; absence of peritoneal fluid showed the best negative likelihood ratio.Multidetector CT findings accurately reveal surgically important bowel and/or mesenteric injury and have a high negative predictive value.

To retrospectively determine the accuracy of direct magnetic resonance (MR) arthrography of the shoulder in patients with recurrent or residual signs and/or symptoms of instability after prior instability repair, with surgical findings as the reference standard.After institutional ethics review board approval was obtained and informed consent was waived, 40 patients (31 men, eight women; mean age, 28 years) with recurrent instability after previous instability repair who underwent direct shoulder MR arthrography before repeat surgery were studied. Two musculoskeletal radiologists reviewed direct MR arthrographic studies by using consensus agreement in a blinded fashion. MR assessment included evaluation of the labrum (overall, superior, anterior and anteroinferior, posterior and posteroinferior), rotator cuff, biceps tendon, articular cartilage, and presence or absence of a Hill-Sachs lesion. Mean interval between MR arthrography and repeat surgery was 6.2 months (range, 6 days to 36 months). Surgical reports were compared with MR arthrographic results, and accuracy, sensitivity, and specificity of direct MR arthrography were determined.Accuracy, sensitivity, and specificity, respectively, of direct MR arthrography in diagnosis of overall labral tears (n = 26) were 91.9%, 96.2%, and 81.8%; those of superior labral tears (n = 16) were 89.2%, 93.8%, and 85.7%; and those of anteroinferior tears (n = 17) were 91.9%, 100%, and 85%. Overall accuracy for detecting rotator cuff injury (n = 17) was 87.2% (sensitivity, 94.1%; specificity, 81.8%); accuracy for biceps injury (n = 7) was 95.7% (sensitivity, 85.7%; specificity, 100%); accuracy for glenoid and/or humeral articular cartilage abnormality (n = 15) was 76.2% (sensitivity, 73.3%; specificity, 83.3%); and accuracy for Hill-Sachs lesion (n = 14) was 93.3%.Direct MR arthrography is accurate (91.9%) for assessing labral pathologic conditions and other internal derangements of the shoulder in patients with recurrent or residual signs and/or symptoms after prior shoulder instability repair.

To determine whether absence of bowel wall perfusion at color Doppler ultrasonography (US) is indicative of bowel necrosis in neonates with necrotizing enterocolitis (NEC).This study was approved by the research ethics board, and informed consent was obtained. Sixty-two neonates enrolled in the prospective study underwent US of the bowel wall. Neonates were divided into two groups. Group A included 30 control subjects with gestational ages (GAs) ranging from 24 to 41 weeks. Group B included 32 neonates with GAs ranging from 24 to 40 weeks who were clinically proved to have or suspected of having NEC. All neonates in group B underwent abdominal radiography. Normative values were calculated in group A. In group B, the sensitivities and specificities of color Doppler US and abdominal radiography for detection of bowel necrosis were computed by using the modified Bell staging criteria for NEC as the reference standard.Two neonates were excluded from group B; thus, a total of 60 neonates were included in the study. In group A, bowel wall thickness ranged from 1.1 to 2.6 mm. Bowel wall perfusion was detected with color Doppler US in all 30 neonates. Color Doppler signals ranged from one to nine dots per square centimeter. Twenty-two of 30 neonates in group B received a diagnosis of NEC. Mild to moderate NEC was diagnosed in 12 neonates. Color Doppler US depicted an isolated segment of bowel-absent blood flow in two neonates; this finding was confirmed with laparotomy. In 10 neonates with severe NEC, color Doppler US depicted isolated or multiple segments of bowel with absent perfusion. Pneumoperitoneum was present in only four neonates. The remaining eight neonates at risk for NEC had no evidence of loops without perfusion at color Doppler US. The sensitivity of free air at abdominal radiography as a positive sign for severe NEC with necrotic bowel was 40% compared with the 100% sensitivity of absence of flow at color Doppler US (P = .03).Color Doppler US is more accurate than abdominal radiography in depicting bowel necrosis in NEC.

To assess magnetic resonance (MR) imaging signs and overall accuracy of MR imaging for detection of osseous invasion by soft-tissue sarcoma, with histopathologic correlation as the reference standard.Preoperative MR images (1.5 T, transverse and longitudinal planes, T1 and T2 weighted) of 56 osseous sites in 51 patients who underwent bone resection at surgery for soft-tissue sarcoma were assessed retrospectively for signs of osseous invasion, by consensus of two readers who were blinded to clinical and histopathologic findings. Delay between MR imaging and surgery averaged 34 days (range, 2-112 days). MR signs assessed included osseous abutment by tumor, maximal diameter of osseous abutment, extent of circumferential abutment of long bones (25%, 25%-50%,50%), cortical destruction, and cortical and medullary signal intensity change on T1- and T2-weighted images. Imaging findings were correlated with histopathologic findings. Sensitivities, specificities, positive and negative predictive values (PPV, NPV), and P values were calculated.Eleven sites (20%) showed osseous invasion histologically (two, cortical; nine, both cortical and medullary). Tumor abutted bone at 44 lesion sites (sensitivity, 100%; specificity, 27%). Maximal diameter of osseous abutment and extent of circumferential abutment did not significantly affect osseous invasion (P =.09 and.11, respectively). On T1- and T2-weighted images, 13 lesion sites showed cortical signal intensity change (sensitivity, 100%; specificity, 96%) and 10 showed cortical destruction (sensitivity, 82%; specificity, 98%). Eleven sites showed decreased medullary T1 signal intensity (sensitivity, 100%; specificity, 96%), and 12 showed increased medullary T2 signal intensity (sensitivity, 100%; specificity, 94%). MR imaging overall had a sensitivity of 100%, specificity of 93%, PPV of 79%, and NPV of 100% for detection of osseous invasion on the basis of any finding of cortical destruction or cortical or medullary signal intensity change on T1- or T2-weighted images (P.001).On T1- and T2-weighted MR images, findings of cortical and medullary signal intensity change and cortical destruction were sensitive and specific for detection of osseous invasion by soft-tissue sarcoma.